The present invention relates to a method for masking through holes in the process of manufacturing printed circuit board.
A printed circuit board, the filling of through holes provided in the printed circuit board with a filler is usually carried out across the entire surface of the substrate by silk screen printing.
Thus, when filling the through holes with the filler over the entire surface of the substrate, it is necessary to first mask the openings of the through holes which are not required to be filled with filler (such as holes for mounting electric components thereon) before preceding to the filling work.
The masking of the openings of such through holes can be performed by manually sticking an adhesive tape made of synthetic resin onto the opening of the through holes requiring masking.
Furthermore, after the completion of the filling step across the entire surface of the substrate followed by the setting of the filler filled in the through holes, the adhesive tape must be manually removed.
Masking the through holes that are not going to be filled is conducted before the filling step during the conventional manufacturing process of the printed circuit board. The masking is manually performed in the transfer step of the substrate, so that it is necessary to perform a complicated procedure such as adhering the adhesive tape. Also cutting work is done by means of a cutter, which results in the surface of the substrate sustaining damage in the cutting work with a cutter, which leads to a defectiveness.
Also, the adhesive tape must be manually peeled off after the filler is set. The peeling work using a cutter is complicated and The adhesive tape that may not be perfectly removed. adhesive agent of the adhesive tape remains on the substrate causes a defective to occur during etching.
In addition, serious drawbacks resulting from peeling off the adhesive tape by a cutter and the like, the set filler may be damaged, the working atmosphere may be deteriorated, deterioration of working atmosphere, or the cutter may damage the surface of the substrate and cause a defective end product.
To overcome the disadvantages of the masking method of the through holes in the conventional process of manufacturing a printed circuit board, the present invention provides a method for masking through holes enabling an easy and quick masking without deteriorating the working atmosphere, as well as an easy and quick release from the masking state.